Existence refers to the state of being, or simply being there. It is the opposite of non-existence, which is the state of not being there. In philosophy, existence is often contrasted with essence, where existence refers to the fact that something is, while essence refers to what something is. The concept of existence is central to many philosophical debates, including those concerning metaphysics, ontology, and epistemology. In Hebrew, existence is translated as קיום (kiyum). In other languages, it is known as Existenz in German, existencia in Spanish, existence in French, and 存在 (sonzai) in Japanese. The question of existence has been explored by various thinkers throughout history, with notable contributions from philosophers such as Aristotle, René Descartes, and Martin Heidegger. In mathematics and logic, existence is often discussed in the context of existential quantifiers, which assert the being of at least one thing having a certain property.